Sickle Cell Success Found

Sickle cell disease corrected with patient's own cells in preclinical study

(RxWiki News) They key to correcting sickle cell disease may lie in a patient's own stem cells. Researchers have found a way to use the cells in a test tube to create a normal version of the gene.

During the laboratory experiment, Johns Hopkins researchers successfully took a patient's own stem cells and coaxed them into immature red blood cells that were transformed into a version of the gene without the sickle cell trait.

"Follow your doctor's treatment plan for sickle cell disease."

Though the research bodes well for curing or better treating the debilitating inherited blood disorder that mostly affects African Americans, it is still several years away from clinical trials in patients.

Drugs, and for some patients, frequent blood transfusions can control the symptoms, but a bone marrow transplant that is rarely achieved because of the difficulty in finding compatible donors is the only way to cure the disorder, said Linzhao Cheng, a professor of medicine and associate director for basic research in the division of hematology at Johns Hopkins Hospital and also a member of the Johns Hopkins Institute for Cell Engineering. Cheng said the research takes investigators one step closer to developing a combination cell and gene therapy method to treat patients with their own stem cells.

Individuals who inherit two copies of the genetic alteration -- one from each parent -- tend to suffer from fatigue, pain, infections, organ damage and even premature death because misshapen sickle-shaped red blood cells clog vessels.

Johns Hopkins Hospital researchers isolated the bone marrow cells of a single adult patient during the study. Those bone marrow cells were used to generate adult cells reprogrammed to behave like embryonic stem cells. Researchers then placed a normal copy of the hemoglobin gene in place of the defective one through genetic engineering techniques.

Growth factors were used to transform the cells into immature red blood cells. Testing showed that the normal hemoglobin gene was turned on, but at less than half of the normal level.

Cheng said it is suspected that the immature red blood cells still behave like embryonic cells and as a result are unable to turn on high enough levels of the adult hemoglobin gene. Investigators now plan to learn how to properly convert the cells into mature red blood cells.

The research was funded by grants from the Maryland Stem Cell Fund and the National Institutes of Health, and a fellowship from the Siebel Foundation. The article was published in journal Blood.

Reviewed by: 
Review Date: 
October 4, 2011